Over deze add-on
In addition, when replying to a mail the extension can check the “To”-address of the received mail and with a regular expression match this address is used as the new “From”-address. Thus ensuring you always reply with the correct identiy.
This extension is a merge of
Flexible Identity (https://addons.mozilla.org/en-US/thunderbird/addon/flexible-identity/)
Reply as Original Recipient (https://addons.mozilla.org/en-US/thunderbird/addon/reply-as-original-recipient/)
with new features added.